The present invention relates to an image recording material. More precisely, the present invention relates to an image recording material that exhibits high sensitivity, low fog and good storage stability, and is stable against fluctuation of development conditions.
A large number of photosensitive materials are known which have a photosensitive layer on a support and form images by exposing them imagewise. They include those utilizing a technique of forming an image by heat development as a system that contributes environmental conservation or simplification of image formation.
In recent years, reduction of amount of waste processing solutions is strongly desired in the field of photomechanical process from the standpoints of environmental protection and space savings. Techniques relating to photothermographic materials for use in photomechanical process are required, which enables efficient exposure by a laser scanner or laser image setter and formation of a clear black image having high resolution and sharpness. Such photothermographic materials can provide users with a simpler and non-polluting heat development processing system that eliminates the use of solution-type processing chemicals.
Methods for forming images by heat development are described in, for example, U.S. Pat. Nos. 3,152,904 and 3,457,075 and D. Klosterboer, xe2x80x9cThermally Processed Silver Systems Axe2x80x9d, Imaging Processes and Materials, Neblette, 8th ed., compiled by J. Sturge, V. Walworth and A. Shepp, Chapter 9, p. 279, (1989). The photothermographic materials contain a reducible non-photosensitive silver source (e.g., silver salt of organic acid), a photocatalyst (e.g., silver halide) in a catalytically active amount, and a reducing agent for silver, which are usually dispersed in an organic binder matrix. These photothermographic materials are stable at an ambient temperature, but when the materials are heated at a high temperature (e.g., 80xc2x0 C. or higher) after light exposure, silver is produced through an oxidation-reduction reaction between the reducible silver source (which functions as an oxidizing agent) and the reducing agent. The oxidation-reduction reaction is accelerated by catalytic action of a latent image generated upon exposure. The silver produced by the reaction of the reducible silver salt in the exposed region provides a black color and this presents a contrast to the non-exposure region to form an image.
U.S. Pat. Nos. 5,496,695, 5,545,515, 5,654,130, 5,705,324 and so forth disclose photothermographic materials providing ultrahigh contrast images that contains an ultrahigh contrast agent. However, in these photothermographic materials, high Dmin due to thermal fog, fluctuation of sensitivity and size of half tone dots depending on change of development conditions and so forth pose serious problems.
For photothermographic materials, increase of sensitivity of the materials is required in view of reduction of costs for development apparatuses, light source used for light exposure such as lasers and so forth. Development enhancers are disclosed in U.S. Pat. Nos. 5,026,633, 5,545,505, 5,545,507, 5,558,983, 5,637,449 and so forth. However, these development enhancers may suffer from disadvantages, for example, their effect may not be sufficient, they may show strong thermal fog upon development, they may show bad storability of images after development and so forth.
Fog is a serious problem in photographic materials. Various researches have been made to reduce the fog in photothermographic materials. For example, U.S. Pat. No. 3,589,903 discloses use of mercury salts. Furthermore, there have also been disclosed uses of carboxylic acids such as benzoic acid and phthalic acid (U.S. Pat. No. 4,152,160), benzoylbenzoic acid compounds (U.S. Pat. No. 4,784,939), indane or tetralincarboxylic acids (U.S. Pat. No. 4,569,906), dicarboxylic acids (U.S. Pat. No. 4,820,617), heteroaromatic carboxylic acids (U.S. Pat. No. 4,626,500), halogenated compounds (U.S. Pat. Nos. 4,546,075, 4,756,999, 4,452,885, 3,874,946 and 3,955,982), halogen molecules or halogen atoms bonded to heterocycles (U.S. Pat. No. 5,028,523), palladium compounds (U.S. Pat. No. 4,103,312 and British Patent No. 1,502,670), iron family compounds (U.S. Pat. No. 4,128,428), substituted triazoles (U.S. Pat. Nos. 4,123,374, 4,129,557 and 4,125,430), sulfur compounds (U.S. Pat. Nos. 4,213,784, 4,245,033, and Japanese Patent Laid-open Publication (Kokai, hereinafter referred to as JP-A) 51-26019), thiouracils (U.S. Pat. No. 4,002,479), sulfinic acid (JP-A-50-123331), metal salts of thiosulfonic acid (U.S. Pat. Nos. 4,125,403, 4,152,160 and 4,307,187) and combinations of metal salts of thiosulfonic acid and sulfinic acid (JP-A-53-20923 and JP-A-53-19825), thiosulfonic acid esters (Japanese Patent Publication (Kokoku, hereinafter referred to as JP-B) 62-50810, JP-A-7-209797 and JP-A-9-43760).
Further, disulfide compounds are disclosed in JP-A-51-42529 and JP-B-63-37368, and polyhalogenated compounds are disclosed in JP-B-54-165. However, those compounds have drawbacks, for example, insufficient anti-fog effect, insufficient storage stability of photosensitive materials before development, insufficient image storage stability after development (for example, coloration of non-image areas caused by heat or light), and decrease of sensitivity and Dmax when those compounds are added in an amount for sufficiently suppress the fog.
An object of the present invention is to solve the aforementioned problems of the prior art. That is, the object of to be achieved by the present invention is to provide an image recording material that exhibits high sensitivity, low fog and good storage stability, and is stable against fluctuation of development conditions.
The inventors of the present invention assiduously studied in order to achieve the aforementioned object. As a result, they found that an excellent image recording material that provides the desired effects could be obtained by using a compound represented by the following Formula (1) in an image forming material, and thus accomplished the present invention.
That is, the present invention provides an image recording material comprising, on a support, a photosensitive silver halide, a reducing agent, a binder and a compound represented by the following Formula (1): 
wherein, in Formula (1), R1 and R2 each independently represent a substituent, R1 and R2 may be bonded to each other to form a ring, X represents a halogen atom, L represents a methylene group, m represents an integer of 0-7, Y represents a divalent bridging group, n represents 0 or 1 and Z represents a residue derived from a photographically useful compound.
Preferably, the image record material of the present invention further contains a reducible silver salt.
Preferably, the image record material of the present invention further contains an ultrahigh contrast agent.
Preferably, the image record material of the present invention is a thermally processed image recording material.
According to the present invention, it became possible to provide an image recording material that exhibits high sensitivity, low fog and good storage stability, and is stable against fluctuation of development conditions.